The present invention relates to a machine for machining edges, particularly of glass plates.
As is known, machines for machining the edges of glass plates, such as for example chamfering machines, generally have, on a supporting structure, a pair of opposite conveyors which extend continuously and retain the plate, arranged edgeways, between them; said plate must be moved to be machined on machining heads which generally have grinders which protrude upward from the machining table.
In order to allow the accommodation of the machining heads, the sliding blocks which retain the glass plates and are provided on the continuously extending conveyors must therefore remain at a certain distance from the machining surface, since they would otherwise interfere with the machining heads.
It is also known that in some cases it is necessary to machine the edges of small glass plates.
Accordingly, in order to try to solve this problem, solutions have already been provided which in practice entail a sliding block which can move with respect to the conveyor along a direction which is substantially perpendicular to said conveyor advancement direction, so that it is possible to retain even small plates.
However, this solution creates considerable disadvantages, since the guides for the translatory motion of the sliding blocks, which are moved monolithically, are unavoidably subjected to very heavy wear, being exposed to the machining dust and waste, which is generally composed of the abrasive compound which constitutes the grinder and of minute glass particles.
In these conditions, the machine is thus subjected to very heavy wear, which is increased by the fact that the sliding blocks are moved continuously, since with the structure according to the known art the sliding block is necessarily arranged in its lowered position along the portion during which it retains the plate but is lifted in the opposite portions, so that the movement is continuous and wear is very heavy.
Furthermore, cam systems are used in order to perform the translatory motion of the sliding block; such systems do not allow to move the conveyors in the opposite direction, as is instead required for maintenance or for special events, since the rollers which must follow the cams would remain in raised position during the reversal step and would consequently interfere with the cams, creating unavoidable breakages.